As a rule, commercial aircraft have an air infeed installation with two mutually independent air infeed systems for air-conditioning the passenger cabin. A central air infeed system which is regulated centrally, for example via the cockpit, serves, above all, for that continuous infeed of fresh air which is necessary because of the large passenger density in an aircraft cabin. Air outlet apertures belonging to the central air infeed system may be disposed both in the foot area of the aircraft's passenger cabin and also in the region of the stowage lockers for luggage which are located above the rows of seats. Apart from this, there is an additional, individually adjustable air infeed system for each individual seating place, which system is connected to so-called “passenger nozzles”. These are located above the passenger seats and can be adjusted individually by each passenger as regards the air flow and direction of flow.
The air-conditioning air to be fed to the aircraft's passenger cabin is cooled or heated and dehumidified in a special unit and passes from the latter, via an air-distributor system, to the two air infeed systems which comprise duct or pipe systems which are constructed so as to be separate from one another. The duct system or pipe system of the individual air infeed system which is used for the individually adjustable infeed of air normally has a smaller cross-section than the duct system or pipe system of the central air infeed system which serves for the centrally regulated ventilation of the passenger cabin.
One problem of separate air infeed systems of this kind lies in their multipart nature, which represents a higher expenditure when fitting is carried out. Thus, it is necessary to fit both the corresponding modules for the individually adjustable infeed of air, and the respective modules for the central infeed of air for cabin ventilation, as separate units in a number of fitting steps. Furthermore, the air infeed systems which have been installed separately and are mutually independent each have to be provided with their own secondary insulation in order to maintain the air temperature of the air-conditioned air within the air infeed system.
A further problem consists in the fact that the two air infeed systems with their separate duct systems take up a relatively large installation space because of the geometry of the individual components. This restricts the installation space available within the aircraft's fuselage for other components. In addition to this, as a result of the restrictions on installation space which exist within the aircraft's fuselage, the individual air infeed elements have to be constructed with small duct cross-sections, and this leads to losses of pressure in the ducts of the air infeed systems. It is therefore usually necessary to generate an additional initial air pressure in order to ensure adequate ventilation of the aircraft's passenger cabin.
The underlying object of the present invention is to make available an air infeed device, and also an air infeed system for air-conditioning passenger areas in aircraft, which is of compact construction and simple to fit.